Stimulation lead and method including a multi-dimensional electrode array

ABSTRACT

Stimulation lead includes an elongated lead body having distal and proximal ends and wire conductors extending therebetween. The stimulation lead also includes a lead paddle having a multi-dimensional array of electrodes positioned along a contact side of the lead paddle. The electrodes are electrically coupled to the wire conductors. The lead paddle includes a paddle body and a conductor organizer disposed within the paddle body. The conductor organizer has multiple channels extending along the lead paddle. The channels receive the wire conductors and retain the wire conductors in a designated arrangement with respect to the lead paddle. The conductor organizer has openings to the channels. The wire conductors extend through the openings and are terminated to the respective electrodes.

BACKGROUND OF THE INVENTION

Embodiments herein generally relate to stimulation therapy, such asspinal cord stimulation (SCS) therapy, and more particularly to systemsand methods including a paddle lead having a multi-dimensional electrodearray.

Stimulation systems are devices that generate electrical pulses anddeliver the pulses to tissue to treat a variety of disorders.Neurostimulation (NS) is the stimulation of nerve tissue, such as thespinal cord or brain. SCS is a common type of neurostimulation. In SCS,electrical pulses are delivered to nerve tissue in the spine typicallyfor the purpose of chronic pain control. While a precise understandingof the interaction between the applied electrical energy and the nervoustissue is not fully appreciated, it is known that application of anelectrical field to spinal nervous tissue can be used to mask certaintypes of pain transmitted from regions of the body associated with thestimulated nerve tissue. SCS may have applications other than painalleviation as well.

NS systems, including SCS systems, generally include a pulse generatorand one or more leads electrically coupled to the pulse generator. Alead includes a lead body having insulative material and an electrodearray that is arranged at an end of the lead body. The electrodes areelectrically coupled to the pulse generator through wire conductors. Thelead is implanted within an individual's body such that the electrodearray is proximate to nervous tissue (e.g., within epidural space of aspinal cord) to deliver the electrical pulses. The pulse generator mayalso be implanted within the individual and may be programmed (andre-programmed) to provide the electrical pulses in accordance with adesignated sequence.

Typically, there are two types of leads that can be used. The first typeis a percutaneous lead, which has a rod-like shape and includeselectrodes spaced apart from each other along a single axis. The secondtype of lead is a paddle lead. A paddle lead has an elongatedmulti-dimensional body at an end of the lead that has a thin,rectangular-like shape (i.e., paddle-like shape). Although thepercutaneous lead may include only one row or column of electrodes, thepaddle lead includes an array of electrodes that are spaced apart fromeach other along more than one dimension. The wire conductors thatdeliver the electrical signals from the pulse generator are electricallyconnected to certain electrodes within the paddle-like body (hereinafterreferred to as the “lead paddle”).

Although paddle leads have been implemented successfully, somechallenges remain. Fabrication of paddle leads can be complex. Also, theelectrical connections within a paddle lead can be subject to failureover time for a variety of reasons.

In addition to the above, the paddle bodies can be rigid or semi-rigid.In SCS, the lead paddle is typically positioned within the epiduralspace adjacent to the dura of the spinal cord. In some instances, thesize of the epidural space and the dimensions of the lead paddle causethe lead paddle to press against the spinal cord. If the compression issubstantial, it may cause unwanted consequences, such as a tinglingsensation, pain, partial paralysis, or even complete paralysis of thelegs.

SUMMARY

In an embodiment, a stimulation lead is provided. The stimulation leadincludes an elongated lead body having distal and proximal ends and wireconductors extending therebetween. The stimulation lead also includes alead paddle having a multi-dimensional array of electrodes positionedalong a contact side of the lead paddle. The electrodes are electricallycoupled to the wire conductors. The lead paddle includes a paddle bodyand a conductor organizer disposed within the paddle body. The conductororganizer has multiple channels extending along the lead paddle. Thechannels receive the wire conductors and retain the wire conductors in adesignated arrangement with respect to the lead paddle. The conductororganizer has openings to the channels. The wire conductors extendthrough the openings and are terminated to the respective electrodes.

In some aspects, the openings are positioned adjacent to respectiveelectrodes of the multi-dimensional array of electrodes.

In some aspects, the conductor organizer includes a plurality of tubesthat are connected to one another side-by-side. The tubes define thechannels. In other aspects, the tubes are not positioned side-by-side.For example, adjacent tubes may be spaced apart by a gap.

In some aspects, the channels extend parallel to one another for atleast a portion of a length of the conductor organizer. In particularaspects, the channels extend parallel to one another for the entirelength of the conductor organizer.

In some aspects, the lead paddle includes an inner frame having oppositefirst and second side surfaces and a flexible layer secured to the firstside surface of the inner frame. For example, the flexible layer may beovermolded with respect to the inner frame. The flexible layer defines aportion of the contact side of the lead paddle. The inner frame may bemore rigid than the flexible layer. The channels of the conductororganizer extend along and parallel to the second side surface of theinner frame.

In some aspects, the inner frame includes frame windows and the flexiblelayer includes layer windows that align with the frame windows to formconductor passages. The wire conductors extend through the conductorpassages and are mechanically and electrically coupled to the respectiveelectrodes. For example, the wire conductors may be welded or solderedto the electrodes.

In some aspects, the electrodes are arranged in columns that extendlongitudinally along the lead paddle. The columns are separated by aspacing. The channels of the conductor organizer may extend along thespacing between the columns of the electrodes.

Optionally, the columns include first and second columns that areadjacent to one another. The channels of the conductor organizer mayextend along the spacing between the first and second columns, whereinat least one of the wire conductors that is received by the channels ofthe conductor organizer is terminated to one of the electrodes of thefirst column and at least one of the wire conductors that is received bythe channels of the conductor organizer is terminated to one of theelectrodes of the second column.

In some aspects, the openings of the conductor organizer include atleast one side opening and at least one distal opening. The distalopening is at an end of the conductor organizer. The side opening isspaced apart from the at least one distal opening of the conductororganizer.

In some aspects, each of the channels receives only one of the wireconductors. In other aspects, however, the channels may be sized andshaped to receive more than one wire conductor.

In some aspects, the conductor organizer includes a plurality ofconductor organizers. Each of the conductor organizers may receive aplurality of the wire conductors.

In an embodiment, a method is provided that includes positioningelectrodes along at least one body layer to form a multi-dimensionalarray and positioning a conductor organizer along the at least one bodylayer. The conductor organizer has multiple channels extendingtherethrough. The method also includes inserting wire conductors intothe channels of the conductor organizer. The conductor organizer retainsthe wire conductors in a designated arrangement with respect to the atleast one body layer. The conductor organizer has openings to thechannels. The wire conductors extend through the openings (e.g., sideopening and/or distal openings). The method also includes electricallycoupling the wire conductors to respective electrodes.

In some aspects, the at least one body layer is a multi-layeredstructure that includes conductor passages that align with respectiveelectrodes. The method may also include directing the wire conductorsthrough the conductor passages.

In some aspects, the at least one body layer has a first lateral sectionand a second lateral section. The method may also include providing alead body having distal and proximal ends. The lead body also includesfirst and second windings of the wire conductors. The first winding iswrapped in a first direction along the lead body. The second winding iswrapped in a second direction along the lead body. The method alsoincludes positioning the first and second windings of the wireconductors onto the at least one body layer. The first winding and thesecond winding are positioned in a splayed configuration such that thefirst winding extends toward the first lateral section and the secondwinding extends toward the second lateral section.

In some aspects, the electrodes are arranged in columns. The columns maybe separated by a spacing. The channels of the conductor organizer mayextend along the spacing between the columns of the electrodes.

In an embodiment, a stimulation lead is provided that includes a leadpaddle having a contact side that includes electrodes. The lead paddlehas a first lateral section and a second lateral section. Thestimulation lead also includes a lead body having a distal and proximalends. The lead body includes first and second windings of wireconductors. The first winding is wrapped in a first direction along thelead body. The second winding is wrapped in a second direction along thelead body. The first winding and the second winding project from thelead body in a splayed configuration such that the first winding extendstoward the first lateral section of the lead paddle and the secondwinding extends toward the second lateral section of the lead paddle.

In some aspects, a bonding material holds the wire conductors of thefirst winding side-by-side to form a first conductor layer and a bondingmaterial holds the wire conductors of the second winding side-by-side toform a second conductor layer. The first and second conductor layersproject from the leady body in the splayed configuration. Optionally,the bonding material for the first and second conductor layers is atleast partially removed after a distance from the lead body.

In some aspects, the lead paddle includes a paddle body and first andsecond conductor organizers disposed within the paddle body. The firstand second conductor organizers have channels extending along the leadpaddle. The channels receive the wire conductors and retain the wireconductors in a designated arrangement with respect to the lead paddle.The first conductor organizer is within the first lateral section, andthe second conductor organizer is within the second lateral section.

In some aspects, the lead body has only a single lumen. The firstwinding of the wire conductors is wrapped about the lumen in a firstdirection and the second winding of the wire conductors is wrapped aboutthe first winding and the lumen in a second direction.

In an embodiment, a method is provided that includes providing amulti-layered structure having a first lateral section and a secondlateral section. The multi-layered structure has electrodes along themulti-layered structure that form a multi-dimensional array. The methodalso includes providing a lead body having distal and proximal ends. Thelead body also includes first and second windings of wire conductors.The first winding is wrapped in a first direction along the lead body,and the second winding is wrapped in a second direction along the leadbody. The method also includes positioning the first and second windingsof the wire conductors onto the multi-layered structure. The firstwinding and the second winding are positioned in a splayed configurationsuch that the first winding extends toward the first lateral section ofthe multi-layered structure and the second winding extends toward thesecond lateral section of the multi-layered structure.

In an embodiment, a stimulation lead is provided that includes anelongated lead body having wire conductors extending between distal andproximal ends of the lead body. The stimulation lead also includes alead paddle coupled to the distal end of the lead body and having acontact side that is configured to face tissue. The contact side has amulti-dimensional array of electrodes that are electrically coupled tothe wire conductors. The lead paddle extends lengthwise along alongitudinal axis, wherein the lead paddle has a neutral plane extendingtherethrough with a neutral longitudinal force envelope (NLFE)surrounding the neutral plane. The lead paddle includes an inner framehaving opposite first and second side surfaces. The first side surfacefaces the contact side. The lead paddle also includes a flexible layersecured to the first side surface of the inner frame and defining aportion of the contact side of the lead paddle. The wire conductorsextend along the second side surface of the inner frame and at least aportion of the wire conductors and inner frame are positioned to extendalong the NLFE such that, when the lead paddle is flexed transverse tothe longitudinal axis by a predetermined amount, the portion of the wireconductors and inner frame within the NLFE experience no more than apredetermined limit of tensile stress or compression stress.

In some aspects, centers of the wire conductors are spaced from thesecond side surface of the inner frame by a distance that is less thantwice a diameter of the wire conductors.

In some aspects, the wire conductors do not cross over one another andthe wire conductors do not cross over the electrodes, except for therespective electrodes that the wire conductors are electrically coupledto.

In some aspects, the lead paddle also includes a backing layer. Theinner frame is disposed between the flexible layer and the backinglayer. The wire conductors extend through the backing layer.

In some aspects, the backing layer includes a back side of the leadpaddle that is generally opposite the contact side. The backing layerdefines raised portions and recessed portions separated by the raisedportions along the back side. The wire conductors extend through therecessed portions.

In some aspects, the flexible layer and the backing layer are shaped toform thin sections of the lead paddle and thick sections of the leadpaddle. The thin sections have a thickness of the lead paddle that isless than a thickness of the thick sections. The wire conductors extendthrough the thin sections.

In some aspects, the inner frame and the flexible layer are a pre-formedmulti-layered structure. The backing layer is molded to the pre-formedmulti-layered structure.

In some aspects, the inner frame includes frame windows and the flexiblelayer includes layer windows that align with the frame windows to formconductor passages. The wire conductors extend through the conductorpassages and are mechanically and electrically coupled to theelectrodes.

In some aspects, the electrodes include projections that extend throughthe flexible layer and couple to the inner frame. The projections arepierced through the flexible layer.

In some aspects, the inner frame includes grooves or channels that alignwith and extend parallel to the wire conductors.

In some aspects, the lead paddle includes a conductor organizer that hasmultiple channels extending through the lead paddle. The channelsreceive the wire conductors. The conductor organizer is configured toretain the wire conductors in a designated arrangement with respect tothe lead paddle. For example, the conductor organizer is configured toretain the wire conductors in a designated arrangement with respect tothe electrodes. The conductor organizer extends through the NLFE.

In some aspects, the lead paddle has a first lateral section and asecond lateral section. The lead body also includes first and secondwindings of the wire conductors. The first winding is wrapped in a firstdirection along the lead body. The second winding is wrapped in a seconddirection along the lead body. The first winding and the second windingproject from the lead body in a splayed configuration such that thefirst winding extends toward the first lateral section of the leadpaddle and the second winding extends toward the second lateral sectionof the lead paddle.

In an embodiment, a method is provided that includes providing amulti-layered structure having an inner frame and a flexible layersecured to the inner frame. The inner frame is more rigid than theflexible layer. The method also includes positioning electrodes alongthe flexible layer to form a multi-dimensional array. The electrodesextend through the flexible layer and couple to the inner frame. Themethod also includes positioning the wire conductors along the secondside surface of the inner frame. The method also includes molding abacking layer to the multi-layered structure to form a lead paddleextending lengthwise along a longitudinal axis. The lead paddle has aneutral plane extending therethrough with a neutral longitudinal forceenvelope (NLFE) surrounding the neutral plane, wherein at least aportion of the wire conductors and inner frame are positioned to extendalong the NLFE such that, when the lead paddle is flexed transverse tothe longitudinal axis by a predetermined amount, the portion of the wireconductors and inner frame within the NLFE experience no more than apredetermined limit of tensile stress or compression stress.

In some aspects, the multi-layered structure includes conductor passagesthat align with respective electrodes. The method also includesdirecting the wire conductors through the conductor passages andpositioning the wire conductors adjacent to the respective electrodes.The method also includes mechanically and electrically coupling the wireconductors to the respective electrodes.

In some aspects, the method also includes positioning a conductororganizer along the inner frame of the multi-layered structure. Theconductor organizer has respective channels that receive the wireconductors.

In some aspects, the wire conductors do not cross over one another andthe wire conductors do not cross over the electrodes, except for therespective electrodes that the wire conductors are terminated to.

In some aspects, the multi-layered structure has a first lateral sectionand a second lateral section. The method also includes providing a leadbody having distal and proximal ends. The lead body also includes firstand second windings of the wire conductors. The first winding is wrappedin a first direction along the lead body. The second winding is wrappedin a second direction along the lead body. The method also includespositioning the first and second windings of the wire conductors ontothe multi-layered structure. The first winding and the second windingproject from the lead body in a splayed configuration such that thefirst winding extends toward the first lateral section of themulti-layered structure and the second winding extends toward the secondlateral section of the multi-layered structure.

In some embodiments, an implantable stimulation lead for stimulation ofneural tissue of a patient is provided. The lead comprises: an elongatedlead body having distal and proximal ends and wire conductors extendingtherebetween; and a paddle structure adapted to be implanted adjacent toneural tissue for electrical stimulation, the paddle structurecomprising a flexible polymer body, electrodes arranged in amulti-dimensional pattern and positioned along a contact side of theflexible polymer body, and a plurality of sets of microtubes with eachmicrotube having an inner lumen; wherein (1) the electrodes areelectrically coupled to the wire conductors of the lead body throughwires positioned within the inner lumens of the plurality of sets ofmicrotubes, (2) each set of microtubes are positioned to extend alongthe paddle structure, and (3) the polymer body of the paddle structureflexes transversely about its longitudinal axis and the plurality ofsets of microtubes are arranged generally parallel to the longitudinalaxis.

A method of fabricating an implantable stimulation lead for provision ofelectrical stimulation to tissue of a patient is provided. The methodcomprises: providing a paddle structure adapted to be implanted adjacentneural tissue for electrical stimulation, the paddle structurecomprising a flexible polymer body; providing electrodes arranged in amulti-dimensional pattern and positioned along a contact side of theflexible polymer body; providing a plurality of sets of microtubes witheach microtube having an inner lumen on the flexible polymer body;routing a wire through each respective microtube of the plurality ofsets of microtubes; and electrically coupling the wires within pluralityof sets of microtubes to respective electrodes positioned along acontact side of the flexible polymer body, wherein the polymer body ofthe paddle structure flexes transversely about its longitudinal axis andthe plurality of sets of microtubes are arranged generally parallel tothe longitudinal axis.

In some embodiments, a method of fabricating a stimulation lead forelectrical stimulation of tissue of a patient is provided. The methodcomprises: providing a paddle structure adapted to be implanted adjacentneural tissue for electrical stimulation, the paddle structurecomprising a flexible polymer body; providing electrodes arranged in amulti-dimensional pattern and positioned along a contact side of theflexible polymer body; providing a plurality of sets of microtubes onthe flexible polymer body, each microtube having an inner lumen;providing a lead body comprising a first plurality of conductor wiresand a second plurality of conductor wires extending between a proximaland distal end of the lead body; routing a conductor wire through theinner lumen of each respective microtube of the plurality of sets ofmicrotubes, wherein the routing comprising separating a first backinglayer for the first plurality of conductor wires and a second backinglayer for the second plurality of conductors wires at a distal end ofthe lead body to couple the first plurality of conductor wires toelectrodes on a first side of the paddle structure and to couple thesecond plurality of conductor wires to electrodes on a second side ofthe paddle structure; and electrically coupling the conductor wireswithin plurality of sets of microtubes to respective electrodespositioned along a contact side of the flexible polymer body, whereinthe polymer body of the paddle structure flexes transversely about itslongitudinal axis and the plurality of sets of microtubes are arrangedgenerally parallel to the longitudinal axis.

In some embodiments, an elongated lead body is provided having distaland proximal ends. The lead body comprises a first plurality of wireconductors and a second plurality of wire conductors extending betweenthe distal and proximal ends, wherein the first plurality of conductorwires are bonded to a first backing layer and the second plurality ofconductor wires are bonded to a second backing layer. The lead bodycomprises a paddle structure adapted to be implanted adjacent to neuraltissue for electrical stimulation, the paddle structure comprising aflexible polymer body, electrodes arranged in a multi-dimensionalpattern and positioned along a contact side of the flexible polymerbody, and a plurality of sets of microtubes with each microtube havingan inner lumen. The first and second plurality of conductor wires extendbeyond the first backing layer and second backing layer at a distal endof the lead body and are positioned within the inner lumens of theplurality of sets of microtube of the paddle structure. The electrodesare electrically coupled to the first and second plurality of wireconductors, (2) each set of microtubes are positioned to extend alongthe paddle structure. The polymer body of the paddle structure flexestransversely about its longitudinal axis and the plurality of sets ofmicrotubes are arranged generally parallel to the longitudinal axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a schematic block diagram of an embodiment of astimulation system that includes a paddle lead.

FIG. 2 depicts a contact side of a lead paddle that may form part of astimulation system, such as the stimulation system of FIG. 1, inaccordance with an embodiment.

FIG. 3 is a top perspective view of the lead paddle of FIG. 2 inaccordance with an embodiment.

FIG. 4 is a flowchart illustrating a method in accordance with anembodiment.

FIG. 5 is a perspective view of an inner frame that may be used tomanufacture the lead paddle of FIG. 2 in accordance with an embodiment.

FIG. 6 illustrates a multi-layered structure having the inner frame anda flexible layer secured to the inner frame in accordance with anembodiment.

FIG. 7 is a perspective view of the multi-layered structure havingelectrodes coupled thereto in accordance with an embodiment.

FIG. 8A illustrates how a single electrode may be shaped to couple tothe multi-layered structure in accordance with an embodiment.

FIG. 8B is a cross-section of the multi-layered structure of FIG. 7taken along lines 8B-8B.

FIG. 9 is a perspective view of the multi-layered structure havingconductor organizers positioned thereon in accordance with anembodiment.

FIG. 10 is an end view of an exemplary conductor organizer in accordancewith an embodiment.

FIG. 11 is a plan view of a multi-layered structure in accordance withanother embodiment that includes conductor organizers positionedthereon.

FIG. 12A is a cross-section of a lead body in accordance with anembodiment.

FIG. 12B is a cross-section of a lead body in accordance with anotherembodiment.

FIG. 13 depicts an end of a lead body in accordance with an embodimentin which two windings of wire conductors form a splayed or butterflyconfiguration.

FIG. 14 is an enlarged perspective view of the multi-layered structureand an end of the lead body, in accordance with an embodiment, in whichtwo windings of wire conductors form a splayed or butterflyconfiguration.

FIG. 15 is an enlarged plan view of the multi-layered structureillustrating an arrangement of the wire conductors that form the splayedconfiguration.

FIG. 16 depicts a wire conductor being mechanically and electricallycoupled to an electrode in accordance with an embodiment.

FIG. 17 depicts a sub-assembly positioned within a mold cavity prior toa backing layer being added, in accordance with an embodiment.

FIG. 18 is an end view of a lead paddle in accordance with anembodiment.

FIG. 19 illustrates a cross-section of the lead paddle taken along lines19-19 in FIG. 3.

FIG. 20 is an enlarged cross-section of the lead paddle that illustratesa neutral longitudinal force envelope (NLFE) of an embodiment.

DETAILED DESCRIPTION

While multiple embodiments are described, still other embodiments of thedescribed subject matter will become apparent to those skilled in theart from the following detailed description and drawings, which show anddescribe illustrative embodiments of disclosed inventive subject matter.As will be realized, the inventive subject matter is capable ofmodifications in various aspects, all without departing from the spiritand scope of the described subject matter. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

Embodiments set forth herein include systems, neurostimulation leads,paddle bodies, and methods relating to the same that use amulti-dimensional electrode array. The electrodes of themulti-dimensional electrode array are capable of generating electricalpulses and delivering the pulses to nerve tissue to treat a variety ofdisorders. For example, one or more embodiments may be configured forspinal cord stimulation (SCS). It is contemplated that embodiments mayhave applications other than pain alleviation.

Paddle bodies set forth herein may be easier to manufacture, may be lesstime-consuming to manufacture, and/or may be less costly to manufacture.One or more embodiments may include paddle bodies that are thinnerand/or more flexible than conventional paddle bodies. As such, thepaddle bodies may reduce the likelihood that the nerve tissue will beunduly compressed. Alternatively, or in addition to the aboveembodiments, at least some embodiments may impede migration of the leadpaddle away from its original position with respect to the nerve tissue.

Optionally, embodiments may be configured to reduce the likelihood thatthe wire conductors will break or otherwise become inoperable for theirintended purpose. For instance, embodiments may have wire conductorsthat are positioned within the lead paddle (or the paddle body) toreduce or minimize an amount of stress that is experienced by the wireconductors when the lead paddle is flexed. To this end, the wireconductors may be positioned along or near a neutral plane of the leadpaddle (or the paddle body). A neutral plane is a conceptual plane thatis used in engineering design. When a structure is flexed or bent withrespect to a relaxed or steady-state position, the neutral plane of thelead paddle separates one region that is in compression and one regionthat is in tension.

As used herein, a “neutral longitudinal force envelope (NLFE)” is aportion of the lead paddle that surrounds the neutral plane of the leadpaddle. When the lead paddle is flexed or bent, the NLFE experiences acompression stress on one side of the neutral plane that is less thanthe compression stress experienced outside the NLFE. On the other sideof the neutral plane, the NLFE experiences a tensile stress that is lessthan the tensile stress experienced outside the NLFE. The amount ofstress (whether tensile or compression) may not exceed an amount ofstress that will cause damage or excessive wear to the lead paddle.

For example, when the lead paddle is flexed transverse to a longitudinalaxis of the lead paddle by a predetermined amount, the wire conductorsand the inner frame within the NLFE may experience no more than apredetermined limit of tensile stress or compression stress. Thepredetermined limit may be, for example, the value at which the wireconductors will break due to the stress and/or the wire conductorsseparate from the electrodes due to the stress. The predetermined limitmay be a function of an expected number of times at which the leadpaddle will be flexed.

The predetermined amount of flexing is an amount that can be experiencedby the paddle lead when operating within expected parameters for theintended application of the paddle lead. For example, if the paddle leadis implanted and positioned adjacent to a portion of the spine (e.g.,for SCS), the predetermined amount of flexing is a function of how muchthe portion of the spine is expected to flex during normal usage.

Either or both of the predetermined limit and the predetermined amountmay be a function of an expected number of times that the lead paddle isexpected to flex. For example, although the wire conductors may notbreak when the lead paddle is flexed X amount, the wire conductors maybreak if the lead paddle is flexed X amount a Y number of times. Forsome applications, it may be expected that the flexing will occur oftenin a single day. As such, the predetermined limit may be configured toaccount for material fatigue that may occur. In some embodiments, whenthe lead paddle is flexed transverse to a longitudinal axis of the leadpaddle by at most a predetermined amount, the wire conductors and theinner frame within the NLFE may experience no more than a predeterminedlimit of tensile stress or compression stress.

As used herein, phrases such as “a plurality of [elements],” when usedin the detailed description and claims, does not necessarily includeeach and every element that a component may have. The component may haveother elements that are similar to the plurality of elements in designor function, but not identical. For example, the phrase “a plurality ofopenings of the conductor organizer [being/having a recited feature]”does not necessarily mean that each and every opening of the conductororganizer has the recited feature. Other openings may not have therecited feature. Accordingly, unless explicitly stated otherwise usingthe phrase “each and every [element] of the [component]” (e.g., “eachand every opening of the conductor organizer [being/having a recitedfeature]”), the component may include similar elements that do not havethe recited feature.

FIG. 1 depicts a schematic block diagram of an embodiment of astimulation system 100. In particular embodiments, the stimulationsystem 100 is a neurostimulation (NS) system 100. The stimulation system100 is configured to generate electrical pulses (e.g., excitationpulses) for application to tissue of a patient according to oneembodiment. For example, the stimulation system 100 may be adapted tostimulate spinal cord tissue, dorsal root, dorsal root ganglion,peripheral nerve tissue, deep brain tissue, cortical tissue, cardiactissue, muscle, digestive tissue, pelvic floor tissue, and/or any othersuitable tissue of interest within a patient's body.

The stimulation system 100 includes an implantable pulse generator (IPG)150 that is adapted to generate electrical pulses for application totissue of a patient. The IPG 150 typically comprises a metallic housingor can 158 that encloses a controller circuit 151, pulse-generatingcircuitry 152, a charging coil 153, a battery 154, a communicationcircuit 155, battery-charging circuitry 156, switching circuitry 157,and/or the like. The communication circuit 155 may represent hardwarethat is used to transmit and/or receive data along a bi-directionalcommunication link (e.g., with a device controller 160).

The controller circuit 151 is configured to control the operation of thestimulation system 100. The controller circuit 151 may include one ormore processors, a central processing unit (CPU), one or moremicroprocessors, or any other electronic component or logic-based devicethat is capable of processing input data according to programinstructions. Optionally, the controller circuit 151 may include and/orrepresent one or more hardware circuits or circuitry that include, areconnected with, or that both include and are connected with one or moreprocessors, controllers, and/or other hardware logic-based devices.Additionally or alternatively, the controller circuit 151 may executeinstructions stored on a tangible and non-transitory computer readablemedium (e.g., the memory 161).

The IPG 150 may include a separate or an attached extension component170. The extension component 170 may be a separate component. Forexample, the extension component 170 may connect with a “header” portion(not shown) of the IPG 150. If the extension component 170 is integratedwith the IPG 150, internal electrical connections may be made throughrespective conductive components. Within the IPG 150, electrical pulsesare generated by the pulse-generating circuitry 152 and are provided tothe switching circuitry 157. The switching circuitry 157 connects tooutputs of the IPG 150. Electrical connectors (e.g., “Bal-Seal”connectors) within a connector portion 171 of the extension component170 or within the IPG header may be employed to conduct variousstimulation pulses. The stimulation pulses are transmitted to one ormore stimulation leads 110. The stimulation leads 110 may be referred toas neurostimulation leads (or NS leads) 110, in particular embodiments,such as those directed toward SCS.

The stimulation lead 110 includes a lead paddle 114 and a terminalsegment 116. The lead paddle 114 has a contact side 118 that isconfigured to face tissue (e.g., nerve tissue) for stimulating thetissue and/or detecting signals from the tissue. The contact side 118includes a multi-dimensional electrode array 111 of electrodes 112. Theterminal segment 116 of the stimulation lead 110 is configured to beinserted within the connector portion 171 or within the IPG header forelectrical connection with respective connectors. The pulses originatingfrom the IPG 150 are provided to the one or more stimulation leads 110.The pulses are then conducted through wire conductors of the stimulationlead 110 and applied to the tissue of a patient via themulti-dimensional electrode array 111. Any suitable known or laterdeveloped design may be employed for connector portion 171.

The lead paddle 114 of the stimulation lead 110 includes the electrodearray 111. For example, in a planar formation on a lead paddle asdisclosed in U.S. Provisional Application No. 61/791,288, entitled,“PADDLE LEADS FOR NEUROSTIMULATION AND METHOD OF DELIVERING THE SAME,”which is expressly incorporated herein by reference in its entirety. Theelectrode array 111 includes a plurality of electrodes 112 that arepositioned in a predetermined arrangement. Each of the electrodes 112 isseparated from other adjacent electrodes 112 by non-conducting portionsof the lead paddle 114. The non-conducting portions may include one ormore insulative materials and/or biocompatible materials to allow thestimulation lead 110 to be implantable within the patient. Non-limitingexamples of such materials include polysulfone (PSU), silicone,silicone-polyurethane (SiPU), polyimide, polyetheretherketone (PEEK),polyethylene terephthalate (PET) film (also known as polyester orMylar), polytetrafluoroethylene (PTFE) (e.g., Teflon), or parylenecoating, polyether bloc amides, polyurethane. The electrodes 112 may beconfigured to conduct pulses through their exposed, uninsulatedsurfaces.

In connection to FIG. 1, the stimulation lead 110 may comprise anelongated lead body 172. The lead body 172 extends between a proximalend 174 and a distal end 176 and has wire conductors, such as the wireconductors 380 in FIG. 12, extending between the distal and proximalends 176, 174. The proximal end 174 may be located adjacent to orinclude the terminal segment 116 having electrodes 117. Fordistinguishing different electrodes, the electrodes 112 may be referredto as paddle electrodes 112 and the electrodes 117 may be referred to asterminal electrodes 117.

The lead paddle 114 is coupled to the lead body 172 at the distal end176. The lead body 172 includes an insulative material and a pluralityof wire conductors that extend through the insulative material. The wireconductors electrically couple the paddle electrodes 112 tocorresponding terminal electrodes 117 of the stimulation lead 110. Theterminal electrodes 117 are adapted to receive electrical pulses fromthe IPG 150 and the paddle electrodes 112 are adapted to apply thepulses to the stimulation target of the patient. It should be noted thatalthough the stimulation lead 110 is depicted with twenty-five (25)paddle electrodes 112, the stimulation lead 110 may include any suitablenumber of paddle electrodes 112 (e.g., less than 25, more than 25) aswell as terminal electrodes, and wire conductors. The arrangement ofelectrodes on the lead paddle 114 and the terminal segment 116 may bepositioned in a variety of arrangements. For example, the electrodes 112may be arranged in a grid (as shown in FIG. 1) or in a staggered manner.Some embodiments may have an irregular arrangement.

Although not required for all embodiments, the lead body 172 of thestimulation lead 110 may be fabricated to flex and elongate uponimplantation or advancing within the tissue (e.g., subcutaneous tissue,nervous tissue) of the patient towards the stimulation target andmovements of the patient during or after implantation. By fabricatingthe lead body 172, according to some embodiments, the lead body 172 or aportion thereof is capable of elastic elongation under relatively lowstretching forces. Also, after removal of the stretching force, the leadbody 172 may be capable of resuming its original length and profile. Forexample, the lead body 172 may stretch 10%, 20%, 25%, 35%, or even up orabove to 50% at forces of about 0.5, 1.0, and/or 2.0 pounds ofstretching force. Fabrication techniques and material characteristicsfor “body compliant” leads are disclosed in greater detail in U.S.Provisional Patent Application No. 60/788,518, entitled “Lead BodyManufacturing,” which is expressly incorporated herein by reference.

For implementation of the components within the IPG 150, a processor andassociated charge control circuitry for an IPG is described in U.S. Pat.No. 7,571,007, entitled “SYSTEMS AND METHODS FOR USE IN PULSEGENERATION,” which is expressly incorporated herein by reference.Circuitry for recharging a rechargeable battery (e.g., battery chargingcircuitry 156) of an IPG using inductive coupling and external chargingcircuits are described in U.S. Pat. No. 7,212,110, entitled “IMPLANTABLEDEVICE AND SYSTEM FOR WIRELESS COMMUNICATION,” which is expresslyincorporated herein by reference.

An example and discussion of “constant current” pulse-generatingcircuitry (e.g., pulse-generating circuitry 152) is provided in U.S.Patent Publication No. 2006/0170486 entitled “PULSE GENERATOR HAVING ANEFFICIENT FRACTIONAL VOLTAGE CONVERTER AND METHOD OF USE,” which isexpressly incorporated herein by reference in its entirety. One ormultiple sets of such circuitry may be provided within the IPG 150.Different pulses on different electrodes 112 may be generated using asingle set of the pulse-generating circuitry 152 using consecutivelygenerated pulses according to a “multi-stimset program” as is known inthe art. Complex pulse parameters may be employed such as thosedescribed in U.S. Pat. No. 7,228,179, entitled “Method and apparatus forproviding complex tissue stimulation patterns,” and International PatentPublication Number WO 2001/093953 A1, entitled “NEUROMODULATION THERAPYSYSTEM,” which are expressly incorporated herein by reference.Alternatively, multiple sets of such circuitry may be employed toprovide pulse patterns (e.g., tonic stimulation waveform, burststimulation waveform) that include generated and delivered stimulationpulses through various electrodes of one or more stimulation leads 110as is also known in the art. Various sets of parameters may define thepulse characteristics and pulse timing for the pulses applied to thevarious electrodes 112 as is known in the art. Although constantexcitation pulse-generating circuitry is contemplated for someembodiments, any other suitable type of pulse generating circuitry maybe employed such as constant voltage pulse generating circuitry.

A device controller 160 may be implemented to charge/recharge thebattery 154 of the IPG 150 (although a separate recharging device couldalternatively be employed), to access memory of the IPG 150, and toprogram the IPG 150 on the pulse specifications while implanted withinthe patient.

The device controller 160 is configured to receive and/or transmitinformation with the stimulation system 100, such as the IPG 150. Thedevice controller 160 may include hardware that is used to transmitand/or receive data along a bi-directional communication link. Thedevice controller 160 may include a transceiver, receiver, transceiverand/or the like and associated circuitry (e.g., antennas) for wirelesslycommunicating (e.g., transmitting and/or receiving) with the stimulationsystem 100. For example, protocol firmware for transmitting and/orreceiving data along the bi-directional communication link may be storedin memory, which is accessed by the device controller 160. The protocolfirmware provides the network protocol syntax for the controller circuit151 to assemble data packets, establish and/or partition data receivedalong the bi-directional communication links, and/or the like. Thebi-directional communication link may be a wireless communication (e.g.,utilizing radio frequency (RF)) link for exchanging data (e.g., datapackets) between the one or more alternative medical imaging systems,the remote server, and/or the like. The bi-directional communicationlink may be based on a standard communication protocol, such as acustomized communication protocol, Bluetooth, and/or the like.

Additionally or alternatively, the device controller 160 may be operablycoupled to a “wand” 165. The wand 165 may be electrically connected to atelemetry component 166 (e.g., inductor coil, RF transceiver) at thedistal end of wand 165 through respective wires (not shown) allowingbi-directional communication with the IPG 150. For example, the user mayinitiate communication with the IPG 150 by placing the wand 165proximate to the IPG 150. Preferably, the placement of the wand 165allows the telemetry system of the wand 165 to be aligned with thecommunication circuit 155 of the IPG 150.

Also, the device controller 160 may permit operation of the IPG 150according to one or more spinal cord stimulation (SCS) programs ortherapies to treat the patient. For example, the SCS program correspondsto the SCS delivered and/or executed by the IPG 150. Each SCS programmay include one or more sets of stimulation parameters of the pulsesincluding pulse amplitude, stimulation level, pulse width, pulsefrequency or inter-pulse period, pulse repetition parameter (e.g.,number of times for a given pulse to be repeated for respective stimsetduring execution of program), biphasic pulses, monophasic pulses, etc.The IPG 150 may modify its internal parameters in response to thecontrol signals from the device controller 160 to vary the stimulationcharacteristics of the stimulation pulses transmitted through thestimulation lead 110 to the tissue of the patient. NS systems, stimsets,and multi-stimset programs are discussed in PCT Publication No. WO01/93953, entitled “NEUROMODULATION THERAPY SYSTEM,” and U.S. Pat. No.7,228,179, entitled “METHOD AND APPARATUS FOR PROVIDING COMPLEX TISSUESTIMULATION PATTERNS,” which are expressly incorporated herein byreference.

FIG. 2 is a plan view of a contact side 202 of a lead paddle 200, andFIG. 3 is a top perspective view of a back side 204 of the lead paddle200. The lead paddle 200 may form part of an NS system, such as thestimulation system 100 (FIG. 1). For example, the lead paddle 200 mayreplace the lead paddle 114 (FIG. 1). The lead paddle 200 is coupled toan elongated lead body 206 at a distal end 208 of the lead body 206 toform a stimulation lead, such as the stimulation lead 110 (FIG. 1).Although not shown, the lead body 206 also has a proximal end, such asthe proximal end 174 (FIG. 1). Wire conductors extend between the distalend 208 and the proximal end. The lead paddle 200 is oriented withrespect to X, Y, and Z axes. As shown in FIG. 3, a longitudinal axis 290extends through the lead paddle 200 along a length of the lead paddle200.

The lead paddle 200 includes electrodes 210 (FIG. 2) and paddle body212. The paddle body 212 includes an insulative material that separates(e.g., electrically isolate) adjacent electrodes 210 from one another.The electrodes 210 are electrically connected to wire conductors 380(shown in FIG. 12A) that extend through the lead body 206 to, forexample, an IPG. The electrodes 210 form a multi-dimensional array 214of the electrodes 210 along the contact side 202. As used herein, a“multi-dimensional array of electrodes” or “multi-dimensional electrodearray” means the electrodes are distributed with respect to one anotheralong at least two dimensions. This is unlike conventional percutaneousleads in which the electrodes are arranged essentially along a singleline. For example, the multi-dimensional electrode array 214 has fivecolumns and four rows. A conventional percutaneous lead has one columnof electrodes.

In some embodiments, a multi-dimensional array of electrodes may have atleast eight (8) electrodes, at least nine (9) electrodes, or at leastten (10) electrodes. In more particular embodiments, themulti-dimensional electrode array has at least 12 electrodes, at least14 electrodes, or at least 16 electrodes. Yet in more particularembodiments, the multi-dimensional electrode array has at least 20electrodes. For example, the multi-dimensional electrode array 214 has20 electrodes.

In FIGS. 2 and 3, the contact side 202 and the multi-dimensionalelectrode array 214 (FIG. 2) appear substantially two-dimensional (e.g.,flat). However, due to the flexibility of the lead paddle 200, thetwo-dimensional electrode array 214 is permitted to flex when operablypositioned. When flexed, the electrodes are distributed with respect toone another along three dimensions (e.g., X, Y, Z).

A paddle body has at least one body layer. In the illustratedembodiment, the paddle body 212 includes three body layers, including aflexible layer 216, a backing layer 218, and an inner frame 220. Thebody layers are stacked or positioned alongside one another. Forexample, the flexible layer 216 and the backing layer 218 are positionedon opposite side surfaces of the inner frame 220. The inner frame 220 isillustrated in phantom in FIG. 2. In the illustrated embodiment, each ofthe body layers extends along substantially an entire width W (FIG. 2)of the paddle body 212 and at least a majority of a length L (FIG. 2).It should be understood that other embodiments may include fewer layersor more layers or that an individual layer may be separated intomultiple sections. It should also be understood that other embodimentsmay have different spatial relationships than those shown in FIGS. 2 and3.

The flexible layer 216, which may also be referred to as a compliantlayer, is secured to the inner frame 220 and defines a portion of thecontact side 202. In some embodiments, the inner frame 220 is more rigid(or have a greater stiffness) than the flexible layer 216 and mayprovide, for example, structural integrity to the paddle body 212 and/orprovide a mechanism for attaching the electrodes 210 to the lead paddle200.

As shown in FIG. 2, the flexible layer 216 is shaped to define raisedregions 222 and recessed regions 224 along the contact side 202. Theraised regions 222 are separated by the recessed regions 224, and therecessed regions 224 are separated by the raised regions 222. In theillustrated embodiment, the raised regions 222 are elongated ridges thatextend parallel to one another. The recessed regions 224 are elongatedgrooves or open-sided channels that extend parallel to one another. Asshown, each of the raised regions 222 and the recessed regions 224extend parallel to the longitudinal axis 290. In other embodiments,however, the raised regions 222 and/or the recessed regions 224 may notbe elongated.

As described herein, the electrodes 210 extend through the raisedregions 222 of the flexible layer 216 and couple to the inner frame 220.The electrodes 210 are surrounded by the raised regions 222. Theflexible layer 216 may support or facilitate securing the electrodes 210to the paddle body 212. For example, a raised region 222 may surround aperipheral edge of a corresponding electrode 210. In some embodiments,the electrodes 210 may pierce or puncture the flexible layer 216 andengage the inner frame 220. Alternatively, the electrodes 210 may beovermolded with the flexible layer 216.

The backing layer 218 may define a coupling portion 240 that surroundsthe lead body 212. As shown in FIG. 3, the backing layer 218 is shapedto define raised portions 232 and recessed portions 234 along the backside 204. The raised portions 232 are separated by the recessed portions234, and the recessed portions 234 are separated by the raised portions232. In the illustrated embodiment, the raised portions 232 areelongated ridges that extend parallel to one another. The recessedportions 234 are elongated grooves or open-sided channels that extendparallel to one another. As shown, each of the raised portions 232 andthe recessed portions 234 extend parallel to the longitudinal axis 290.

As described herein, in some embodiments, at least some of the recessedportions 234 of the backing layer 218 and at least some of the recessedregions 224 of the flexible layer 216 align with one another. At leastsome of the raised portions 232 of the backing layer 218 and at leastsome of the raised regions 222 of the flexible layer 216 align with oneanother.

Embodiments may require less space than conventional lead paddles thatcover a similar area along the tissue. In other words, embodiments maybe thinner than conventional lead paddles. For example, the width W ofthe lead paddle may be, at most, 12 millimeters. The width W is amaximum distance between opposite lateral edges of the paddle body andis measured when the paddle body is essentially flat. For example, thewidth W is measured along the X axis when faces of the electrodes of thecontact side coincide with a common plane. The lead paddle 200 in FIG.18 is essentially flat. In certain embodiments, the width W is at most10 mm. The length L may be, for example, at most 60 mm or at most 55 mm.The length L is a maximum distance between distal and proximal oppositeedges of the paddle body and is measured along the longitudinal axiswhen the paddle body is essentially flat.

A thickness T (FIG. 18) may be, for example, at most 2 mm or at most 1.7mm. The thickness T is a maximum distance between the contact and backsides of the paddle body and is measured along the Z axis when thepaddle body is essentially flat. As described herein, embodiments mayhave recesses or gaps that reduce a volume of the paddle body. A volumeof the lead paddle may be, for example, at most 500 mm³ or at most 450mm³. The volume of the lead paddle may be determined, for example, byusing the measurements of the lead paddle to calculate the volume. Thevolume of the lead paddle may also be determined by calculating thedifference in volume of liquid in a container before and after the leadpaddle is placed within the container. Other possible methods may beused. In certain embodiments, the volume of the lead paddle 200 may be,for example, at most 400 mm³ or at most 350 mm³. In particularembodiments, the volume of the lead paddle 200 may be, for example, atmost 300 mm³ or at most 275 mm³.

FIG. 4 is a flowchart illustrating a method 250 in accordance with anembodiment. The method 250 may be, for example, a method ofmanufacturing a stimulation lead. The method 250, for example, mayemploy structures or aspects of various embodiments (e.g., systemsand/or methods) discussed herein. In various embodiments, certain stepsmay be omitted or added, certain steps may be combined, certain stepsmay be performed simultaneously, certain steps may be performedconcurrently, certain steps may be split into multiple steps, certainsteps may be performed in a different order, or certain steps or seriesof steps may be re-performed in an iterative fashion.

The description of FIGS. 5-16 will refer to the method 250 shown in FIG.4. The following description of the method 250 and the lead paddle 200(FIG. 2) illustrates one embodiment. It should be understood that anumber of modifications or changes may be made to the lead paddle 200and/or the method 250. The method 250 includes providing, at 252 (FIG.4), the inner frame 220 as shown in FIG. 5. The inner frame 220 includesa material sheet 225. The material sheet 225 may be a single piece, asshown in FIG. 5, or maybe two or more separate sections. The materialsheet 225 may comprise a thermoplastic material. Non-limiting examplesof material that may be used for the inner frame 220 include polysulfone(PSU), polyether ether ketone (PEEK), polyurethane, SiPU, or a glassfiber reinforced polymer.

The inner frame 220 has a first side surface 302, a second side surface304, and a thickness 305 extending therebetween. In the illustratedembodiment, the thickness 305 is essentially uniform, but otherembodiments may utilize inner frames 220 that have portions withdifferent thicknesses. The thickness 305 may be, for example, at most0.200 mm (0.008 inches (in)) or, more particularly, at most 0.150 mm(0.006 in). In particular embodiments, the thickness may be at most0.130 mm (0.005 in). As more advanced polymers are developed, it may bepossible to use thinner inner frames. Although some embodiments mayutilize inner frames with relatively small thicknesses, largerthicknesses may be used. For example, in other embodiments, thethickness 305 is greater than 0.200 mm or greater than 0.500 mm.

The inner frame 220 has an outer frame edge 315. The outer frame edge315 defines a profile or perimeter of the inner frame 220. The innerframe 220 may be patterned (e.g., laser cut, etched, stamped) to includedesignated features, such as grooves or openings. For example, the innerframe 220 includes frame windows 306, frame grooves 308, longitudinalthru-channels 310, lateral thru-channels 312, alignment openings 314,and coupling openings 316. The openings are defined by edges, such asthe outer frame edge 315 or an inner frame edge 317. The designatedfeatures may have one or more functions. For example, the frame windows306 may be sized and shaped to allow wire conductors 380 (FIG. 12A) tobe positioned adjacent to non-contact faces 345 (FIG. 8B) of theelectrodes 210 (FIG. 2).

The frame grooves 308 and the longitudinal thru-channels 310 extendparallel to the longitudinal axis 290. The frame grooves 308 extendpartially into the thickness 305 of the inner frame 220. Thelongitudinal thru-channels 310 extend entirely through the thickness305. As shown, a plurality of the frame grooves 308 and a plurality ofthe longitudinal thru-channels 310 are aligned with one another in analternating manner. Aligned frame grooves 308 and longitudinalthru-channels 310 may collectively form a corresponding fold line 320.In FIG. 5, the inner frame 220 includes four fold lines 320, but mayinclude fewer or more fold lines in other embodiments. The fold lines320 reduce a lateral stiffness of the paddle body 212 (FIG. 2) andpermit the paddle body 212 to fold or flex about the fold lines 320.

Optionally, a fold line may include only a single frame groove ormultiple frame grooves without a longitudinal thru-channel. In otherembodiments, a fold line may include only a single longitudinalthru-channel or multiple longitudinal thru-channels without a framegroove. The longitudinal thru-channel may extend partially along thelength L or entirely along the length L. For embodiments in which thelongitudinal thru-channel extends along the entire length L, the innerframe 220 may include multiple discrete sections.

The lateral thru-channels 312 extend entirely through the thickness 305.The lateral thru-channels 312 extend parallel to the X axis. Similar tothe longitudinal thru-channels 310, the lateral thru-channels 312 mayalign with other lateral thru-channels 312. The aligned lateralthru-channels 312 may form a fold line 322 that reduces a longitudinalstiffness of the paddle body 212 and permits the paddle body 212 to foldor flex about the fold line 322. The inner frame 220 includes three foldlines 322 in FIG. 5, but may include fewer or more fold lines in otherembodiments.

Optionally, the inner frame 220 includes inner thru-channels 319. Theinner thru-channels 319 may be shaped to provide tab sections 324. Theinner thru-channels 319 and the tab sections 324 may also reduce alongitudinal stiffness of the paddle body 212.

The coupling openings 316 are sized and shaped to receive portions ofthe electrodes 210. For example, the electrodes 210 (FIG. 2) may includeone or more projections 344, 346 (shown in FIG. 8A) that extend throughthe coupling openings 316 and are deformed to grip the inner frame 220.The alignment openings 314 are configured to receive posts or otherprojections of a molding apparatus so that the inner frame 220 may beproperly positioned before a molding process.

Optionally, the openings and thru-channels may be located to allowpolymer or other suitable material (e.g., silicone) to flow during amold process. For example, the longitudinal thru-channels 310, thelateral thru-channels 312, and other openings may permit the backinglayer 218 to flow partially therethrough. After the backing layer 218has cured or solidified, the backing layer 218 may provide a rubber-bandlike effect that mechanically retains the inner frame 220. As such, theopenings may add to the flexibility of the paddle lead 200 and alsoreduce the likelihood that the different layers of the paddle body 212will separate.

The method 250 may also include securing, at 254, the flexible layer 216(FIG. 6) to the inner frame 220. For example, the inner frame 220 may bepositioned within a cavity of a molding apparatus (not shown). Amaterial, which may be a mixture of two or more materials, may beinjected into the cavity. In some embodiments, the material may beliquid silicone rubber (LSR), but other materials may be suitable.Through pressure, heat, and/or a catalyst, the material is permitted tosolidify into the flexible layer 216. The flexible layer 216 may bereferred to as an overmold layer as the material may be permitted toflow into channels, openings, or other available space and effectivelysurround a portion of the inner frame 220. For example, in theillustrated embodiment, the flexible layer 216 extends around the outerframe edge 315. The backing layer 218 may also extend around the outerframe edge 315 and interface with the flexible layer 216. In suchembodiments, the inner frame 220 is encased within the paddle body 212and material of the backing layer 218 and/or material of the flexiblelayer 216 exists between the outer frame edge 315 and an exterior of thepaddle body 212.

When secured to one another as shown in FIG. 6, the flexible layer 216and the inner frame 220 may be referred to as a multi-layered orcomposite structure 340. In some embodiments, the multi-layeredstructure 340 is made prior to adding subsequent elements (e.g., backinglayer). In such instances, the multi-layered structure 340 may bereferred to as a pre-formed structure or, for instances in which theflexible layer 216 is molded, a pre-molded multi-layered structure 340.

As shown in FIG. 6, the flexible layer 216 may include layer windows326. In some embodiments, the layer windows 326 are defined during themolding process at 254. In other embodiments, the layer windows 326 maybe formed subsequently (e.g., through stamping). The flexible layer 216may also be molded to include the raised regions 222 (FIG. 2) and therecessed regions 224 (FIG. 2). Alternatively, the raised regions 222 andthe recessed regions 224 may be formed subsequently by removing materialfrom the flexible layer 216. For instance, after the flexible layer ismade, material from the flexible layer may be removed to form recessedregions and, consequently, raised regions.

The layer windows 326 may align with the frame windows 306 to formconductor passages 328. The conductor passages 328 are sized and shapedto permit the wire conductors 380 (FIG. 12A) to extend therethrough sothat the wire conductors may be mechanically and electrically coupled tothe respective electrodes 210.

FIG. 7 is a perspective view of the multi-layered structure (ormulti-layered structure) 340. FIG. 8A is an isolated view of a singleelectrode 210, and FIG. 8B is a cross-section of the multi-layeredstructure 340 in FIG. 7 taken along lines 8B-8B. At 256 of the method250 (FIG. 4), the electrodes 210 may be attached to the multi-layeredstructure 340. The electrodes 210 may be stamped and formed. As shown inFIGS. 8A and 8B, the electrode 210 includes a contact segment 342 andprojections 344, 346 (FIG. 8A). The contact segment 342 has a contactface 343 that is configured to interface with the tissue. Theprojections 344, 346 are tabs in the illustrated embodiment, but maytake other shapes in other embodiments. As shown in FIG. 8A, theprojections 344, 346 are deformed in a manner that is similar tostapling.

FIG. 8B also shows the raised regions 222 and the recessed regions 224.The electrodes 210 extend through corresponding raised regions 222 ofthe flexible layer 216 and couple to the inner frame 220. As shown, theprojection 344 grips the inner frame 220 and holds the electrode 210against the flexible layer 216. The electrodes 210 may be secured to themulti-layered structure 340 through a coupling process, which may besimilar to a stapling process in some embodiments. For example, theprojections 344, 346 may pierce or puncture the flexible layer 216 andextend through the coupling openings 316. The material of the flexiblelayer 216 is displaced during the piercing or puncturing process. Afteror as the projections 344, 346 advance through the coupling openings316, the projections 344, 346 (FIG. 8A) are deformed to be pressedagainst the second side surface 304 of the inner frame 220.

In some embodiments, the flexible layer 216 may include seating spaces350 that are sized and shaped to receive the contact segments 342. Theseating spaces 350 may be shaped with the layer windows 326 (FIG. 6). Inother embodiments, the flexible layer 216 is not shaped to includeseating spaces. Instead, the stapling process in which the electrodes210 are secured to the multi-layered structure 340 may partially formthe seating spaces by displacing material of the flexible layer 216.Alternatively, the seating spaces may not exist after the staplingprocess. As shown in FIG. 8B, the contact face 343 of the contactsegment 342 may be pitted to include micro-dimples. The electrodes 210may comprise a suitable conductive material. For example, the electrodes210 may comprise platinum and iridium.

In FIG. 8, the electrodes 210 are surrounded by the corresponding raisedregions 222. Specifically, the material of the flexible layer 216engages (e.g., presses against) and surrounds the projections 344, 346such that the projections 344, 346 are held in fixed positions. Thematerial of the flexible layer 216 also exists between the non-contactface 345 of the contact segment 342 and the first side surface 302 ofthe inner frame 220. The material of the flexible layer 216 may becompressed between the inner frame 220 and the contact segment 342.Accordingly, the flexible layer 216 and the inner frame 220 hold theelectrodes 210 in substantially fixed positions.

FIG. 9 is a perspective view of the multi-layered structure 340 havingconductor organizers 352A-352D positioned thereon, and FIG. 10 is an endview of a first organizer end 364 of the conductor organizer 352A. Theconductor organizers 352A-352D include organizer channels 354 (FIG. 10)and are configured to facilitate positioning the wire conductors 380(FIG. 12A) during assembly. For example, the conductor organizers352A-352D may route (or direct) the wire conductors 380 to designatedpositions along the paddle body 212 (FIG. 1) as the wire conductors 380are moved through the conductor organizers 352A-352D. The conductororganizers 352A-352D are also configured to retain the wire conductors380 therein while other elements (e.g., other wire conductors) are beingmoved or assembled. Each of the conductor organizers 352A-352D extendsbetween the first organizer end 364 and a second organizer end 370.

At 258 of the method 250 (FIG. 4), one or more conductor organizers maybe positioned along the inner frame (or the multi-layered structure).With respect to FIG. 9, the contact side 202 and the conductororganizers 352A-352D are positioned on opposite sides of the inner frame220. For example, the conductor organizer 352A has a plurality of theorganizer channels 354 (shown in FIG. 10) that are sized and shaped toretain the wire conductors 380. In the description and claims, theorganizer channels 354 may be referred to as “organizer channels” orsimply as “channels.” Although a more detailed description is providedfor the conductor organizer 352A, the other conductor organizers352B-352D may have similar features.

In certain embodiments, the conductor organizers are discrete elementssuch that the conductor organizers are separate and distinct elementswith respect to the body layers of the paddle body as the paddle body isassembled. For example, with respect to the paddle body 212 (FIG. 2),the conductor organizers 352A-352D may be separate and distinct elementswith respect to the flexible layer 216, the backing layer 218 (FIG. 3),and/or the inner frame 220 as the paddle body 212 is assembled. Theconductor organizers 352A-352D may or may not comprise the same materialas one of the body layers. For instance, in some embodiments, theconductor organizer may comprise the same material as the inner frame.In such instances, however, the conductor organizers and the inner framemay be separate parts.

In other embodiments, however, the inner frame may also function as aconductor organizer. For instance, the inner frame may providestructural integrity to the paddle body and/or provide a mechanism forattaching the electrodes to the lead paddle, but also provide amechanism for routing and retaining the wire conductors. As an example,the inner frame may include tabs that extend away from the planar bodyof the inner frame. The tabs may be used to generally retain the wireconductors in position prior to terminating the wire conductors to theelectrodes and/or molding the backing layer to the multi-layeredstructure.

In some embodiments, however, the conductor organizers comprise adifferent material with respect to the body layer(s). For example, theconductor organizers 352A-352D may comprise a suitable thermoplastic orpolymer material, such as polycarbonate polyurethane (PCU).

In the illustrated embodiment, the conductor organizers 352A-352D aresubstantially planar structures that each extend along a linear paththat is parallel to the longitudinal axis 290 (FIG. 3). In otherembodiments, the conductor organizers 352A-352D may follow paths thatare not linear.

Accordingly, the conductor organizers 352A-352D are configured toprovide multiple channels 354. The channels 354 are configured toreceive the wire conductors 380 (FIG. 12A) and retain the wireconductors 380 in a designated arrangement with respect to the leadpaddle 200 (FIG. 1) or the paddle body 212 (FIG. 1). Specifically,interior surfaces 372 that define the channels 354 are configured toretain the wire conductors in a designated arrangement with respect tothe lead paddle 200.

As shown in FIG. 9, each of the conductor organizers 352A-352D hasproximal openings 366, distal openings 368, and at least one sideopening 356. The proximal openings 366 may be referred to as inletopenings 366 as the wire conductors may be initially inserted throughthe openings 366. The distal openings 368 and the side openings 356 maybe referred to as outlet openings as the wire conductors may exit thechannels 354 through the outlet openings. The proximal openings 366 arealso shown in FIG. 10. The proximal openings 366 are openings torespective channels 354 and are sized and shaped to receive one or morewire conductors 380 (FIG. 12A). The distal openings 368 are associatedwith the channels 354 and are sized and shaped to permit the wireconductors 380 to exit the channel 354. However, at least some of thedistal openings 368 may not have a wire conductor extendingtherethrough. Each of the channels 354 has at least one proximal opening366 and at least one side opening 356 and/or at least one distal opening368. As shown, each of the side openings 356 is spaced apart from thedistal openings 368 of the same conductor organizer and is positionedalong a side of the corresponding conductor organizer. Each side opening356 is accessed through the side of the corresponding conductororganizer. The side openings 356 open in one of two directions along theX axis. The proximal and distal openings 366, 368 open in oppositedirections along the Y axis.

With respect to FIG. 9, the side openings 356 are sized and shaped topermit the wire conductors 380 to extend through the side openings 356and be terminated to the respective electrodes 210. Each channel 354 maybe associated with zero side openings, one side opening, or more thanone side opening (e.g., two or three side openings).

In the illustrated embodiment, each of the conductor organizers 352includes a plurality of tubes 358. The tubes 358 are sized and shaped toreceive only a single wire conductor 380 (FIG. 12A). In otherembodiments, however, the tubes may be sized and shaped to receive morethan one wire conductor (e.g., two, three, or more). As shown, the tubes358 are connected side-by-side and extend parallel to one another. Thechannels 354 extend parallel to one another for at least a portion of alength of the conductor organizer 352. In the illustrated embodiment,the channels 354 extend parallel to one another for an entire length ofthe conductor organizer 352. Optionally, the tubes may not be paralleland may take different paths.

In certain embodiments, the tubes 358 and/or the channels 354 arecapable of being essentially coplanar when the lead paddle 200 is flat.For example, a plane P intersects each of the four channels 354 when thelead paddle 200 (FIG. 1) is flat. The conductor organizers 352A-352D areessentially two-dimensional structures and extend parallel to the X andY axes. However, the conductor organizers 352A-352D may permit flexingor bending during the lifetime operation of the lead paddle 200. Inother embodiments, the conductor organizer may have a morethree-dimensional structure such that the tubes and/or channels mayshift along the Z-axis.

Each of the conductor organizers 352A-352D may be configured to receivea plurality of the wire conductors 380. As shown in FIG. 9, theconductor organizers 352A-352D may be positioned between series ofelectrodes 210. For example, the multi-dimensional array 214 includescolumns 360 of the electrodes 210. The columns 360 extend longitudinallyalong the lead paddle 200 or parallel to the longitudinal axis 290. Assuch, the channels 354 of each of the conductor organizers 352A-352D aredisposed between the electrodes 210 of adjacent columns 360 or extendparallel to and along a spacing that exists between the adjacent columns360. The channels 354 of each conductor organizer 352 are disposedbetween the projections 344, 346 (in FIG. 9). In some embodiments, thewire conductors 380 (FIG. 12A) are positioned to extend between adjacentcolumns 360 without crossing over an electrode 210.

The tubes 358 are interconnected by shared walls 463. Tubes 358A and358D may be referred to as outer tubes, and the channels 354 of thetubes 358A, 358D may be referred to as outer channels. Tubes 358B and358D may be referred to as inner tubes and the channels 354 of the tubes358B, 358C may be referred to as inner channels. If a fifth tubeexisted, the middle tube may be referred to as the center tube having acenter channel. In alternative embodiments, the tubes 358 may beseparated such that a gap exists between adjacent tubes 358. In suchembodiments, the conductor organizers may include bridges that extendlaterally across the conductor organizers and joins each of the tubes.

FIG. 11 is a plan view of a portion of a multi-layered structure 440 inaccordance with another embodiment that includes conductor organizers452A-452E positioned thereon. The multi-layered structure 440 will formpart of a lead paddle (not shown) that includes eighteen (18) electrodes410. The electrodes 410 form a multi-dimensional array 412 havingcolumns 414 and rows 416. The columns 414 extend lengthwise along the Yaxis, and the rows extend lengthwise along the X axis. Although themulti-dimensional array 412 is shown as a grid-type array, it should beunderstood that the electrodes 410 may have other positions with respectto one another. For instance, the electrodes 410 may be staggered orhave an irregular arrangement (e.g., one portion of the array 412 mayhave a greater density of electrodes than another portion).

The conductor organizers 452A-452E are configured to retain the wireconductors, such as the wire conductors 380 (FIG. 12A), in a designatedarrangement with respect to the lead paddle. Each of the conductororganizers 452A-452E include first and second organizer ends 464, 470and plurality of interconnected tubes 458 that are coupled side-by-side.Each of the tubes 458 defines a channel in which the channels of thecorresponding conductor organizer are essentially coplanar when the leadpaddle is flat. For example, a plane extending parallel to the X and Yaxes may intersect each of the tubes 458 or each of the channels thatare defined by the tubes 458.

The channels (or the tubes 458) of the conductor organizers 452A-452Eare disposed between the electrodes 410 of adjacent columns 414 orextend parallel to and along a spacing 492 that exists between theadjacent columns 414. The spacing 492 is a region of the paddle bodythat exists between the electrodes 410. The spacing 492 may includeportions of the paddle body and is not required to be empty space. Inalternative embodiments, one or more of the conductor organizers mayextend over a column or row of the multi-dimensional array. In suchinstances, the side openings may open directly above a respectiveelectrode.

In the illustrated embodiment, each of the conductor organizers452A-452E also includes proximal openings 466 and distal openings 468.The conductor organizers 452A-452E also include side openings. Referencenumerals 471-481 more particularly identify the side openings. As shownin FIG. 11, the side openings of the conductor organizers 452A-452E arearranged such that the side openings are positioned adjacent torespective electrodes 410 of the multi-dimensional array 412. Forinstance, the conductor organizer 452A includes a left-side opening 471having a first depth, a right-side opening 472 having the first depththat is opposite the left-side opening 471, and a right-side opening 473having a second depth that is greater than the first depth. The depthsare measured along the X axis. Openings with the first depth provide anexit point for wire conductors extending through an outer channel of theconductor organizer. Openings with the second depth provide an exitpoint for wire conductors extending through an inner channel of theconductor organizer.

Furthermore, the conductor organizer 452B includes a left-side opening474 having a first depth and a right-side opening 475 having the firstdepth. The conductor organizer 452C includes a left-side opening 476having a first depth and a right-side opening 477 having the firstdepth. The conductor organizer 452D includes a left-side opening 478having a first depth, a left-side opening 479 having the second depth,and a right-side opening 480 having the first depth. The conductororganizer 452E includes a left-side opening 481 having a first depth anda left-side opening 482 having the second depth.

During assembly the conductor organizers 452A-452E may enable routingand retaining the wire conductors in a manner that is morecost-efficient and/or less time-consuming. For example, the conductororganizer 452D is positioned between adjacent first and second columns414 ₁, 414 ₂ of the electrodes 410. The channels of the conductororganizer 452D extend along the spacing 492 between the first and secondcolumns 414 ₁, 414 ₂. At least one wire conductor received by theconductor organizer 452D may be terminated to a respective electrode 410of the first column 414 ₁ and at least one wire conductor received bythe conductor organizer 452D may be terminated to a respective electrode410 of the second column 414 ₂. Moreover, at least one wire conductorreceived by the conductor organizer 452D may extend through a distalopening 468 of the conductor organizer 452D and be terminated to arespective electrode 410 of the first column 414 ₁ or a respectiveelectrode 410 of the second column 414 ₂.

FIGS. 10 and 11 illustrate different configurations of multi-dimensionalarrays and conductor organizers. It is contemplated that a variety ofother configurations of multi-dimensional array and shapes of conductororganizers may be used. By selecting the configuration of themulti-dimensional array, the shape of the conductor organizers, thenumber of channels, and the depth and locations of the side openings,the conductor organizers may be configured to provide openings (e.g.,side openings or distal openings) that render handling the wireconductors during assembly easier. For example, in particularembodiments, the conductor organizers may be configured to provideopenings (e.g., side openings or distal openings) that are adjacent torespective electrodes. An opening may be adjacent to a respectiveelectrode if (a) no other opening for a wire conductor is closer to therespective electrode and (b) the wire conductor extending through theopening does not cross over another electrode.

It should be understood that one or more embodiments include a conductororganizer having at least one opening that is adjacent to the respectiveelectrode(s) and at least one opening that is not adjacent to therespective electrode(s). In some embodiments, a majority of the openingsare adjacent to the electrodes. In other embodiments, however, all or amajority of the openings are not adjacent to respective electrodes.Nonetheless, such embodiments may retain the wire conductors for adesignated length thereby making it easier to control the plurality ofwire conductors during assembly.

Also shown in FIG. 11, the first organizer ends 464 of the differentconductor organizers may have different shapes. For example, the firstorganizer end 464 of the conductor organizer 452A is shaped to facegenerally toward the distal end of the lead body. The first organizerends 464 of the conductor organizer 452B, 452C, and 452D are flat endsthat extend transverse to a length of the conductor organizer. The firstorganizer end 464 of the conductor organizer 452E is shaped to facegenerally toward the distal end of the lead body. In such embodiments,it may be easier and/or require less time for inserting the wireconductors, such as those that are positioned in a splayed configurationas described herein.

FIGS. 12A and 12B illustrate side cross-sections of respective leadbodies that may each be used in accordance with an embodiment. Leadbodies of some embodiments may be similar to lead bodies described inU.S. Patent Application Publication No. 2017/0080213, which is herebyincorporated by reference in its entirety. FIG. 12A is a sidecross-section of the lead body 206. The lead body 206 includes aplurality of wire conductors 380. The lead body 206 is symmetric andincludes one or more lumen 402 configured to receive a guide wire,stylus, or other device to facilitate implant of the lead body 206. Alongitudinal axis 490 extends through a geometric center of the lumen402. The lumen 402 is defined by and surrounded by an inner sheath 404and an outer sheath 406. The inner and outer sheaths 404 and 406 enclosea first (or inner) winding 411 and a second (or outer) winding 413 ofthe wire conductors 380.

The first and second windings 411, 413 form a multi-layer coil 415 inwhich each of the first and second windings 411, 413 is wound about thelumen 402 and extends at least partially along a length of the lead body206. The first winding 411 includes multiple winding turn segments thatare wound about the lumen 402 in a first direction 417 about the lumen402. The second winding 413 includes multiple winding turn segments thatare wound about the first winding 411 in a second direction 418 aboutthe lumen 402. Each wire conductor 380 may be helically wrapped alongthe lead body 206.

The turn segments 427 of the inner winding 411 are wound about the lumen402 at a designated pitch angle (also referred to as a condensed pitchangle) relative to the longitudinal axis 490. The pitch angle representsthe rise over run. For example, the turn segments 427 are oriented at anacute pitch angle Θ₁ of between 30 and 50° relative to the longitudinalaxis 490. As a further example, the turn segments 427 may be oriented atan acute pitch angle Θ₁ of approximately 30°. The turn segments 428 ofthe second winding 413 are wound about the first winding 411 and thelumen 402 at a designated pitch angle relative to the longitudinal axis490. For example, the turn segments 428 are oriented at an acute pitchangle Θ₂ of between 30 and 50° relative to the longitudinal axis 490. Asa further example, the turn segments 428 may be oriented at an acutepitch angle Θ₂ of approximately 30°. The first and second pitch anglesΘ₁ and Θ₂ may be the same (e.g., common) or may be different, dependingupon various factors, such as the difficulty of manufacture, the size ofthe wire conductors 380 for the first and second windings 411, 413,which may be different and, the number of windings, and a level ofelasticity desired in the lead body. The pitch angles Θ₁, Θ₂ may beadjusted, based on the degree to which the pitch angle renders the firstand second windings 411, 413 difficult to manufacture.

The inner sheath 404 may comprise a tubular low-friction interior layerof a relatively high durometer, low friction, polymer-based materialsuch as a thermoplastic polyurethane elastomer or other low-frictionmaterial configured to accommodate (and permit free movement of) astylet or other guide device within the lumen 402. An outer surface ofthe inner sheath 404 may be coated with a layer 420 of an elastomericpolymer, such as a thermoplastic polyurethane elastomer. A durometerhardness (shore) for the material used to make the inner sheath 404 orthe material used to make the layer 420 may be, for example, 50 or moreusing the ASTM D 2240 testing method.

Each of the wire conductors 380 is an insulated conductor having aninsulation layer 422 that surrounds a metal conductor 424. Theinsulation layer 422 may be, for example, ethylene tetrafluoroethylene(ETFE) which has a relatively high melting temperature and highresistance properties. Optionally, the insulation layer 422 may befurther coated with a jacket layer 425 (e.g., biocompatible layer), suchas a thermoplastic polyurethane elastomer. In FIG. 12A, the first andsecond windings 411, 413 of the wire conductors 380 have been reflowedsuch that the jacket layers 425 of the wire conductors 380 join oneanother. The layer of combined material from the jacket layers 425 maybe referred to as a bonding layer because the material holds the wireconductors of the same winding together.

Optionally, the wire conductors of a respective winding may be unwoundas a group. The bonding material and the wire conductors of therespective group may form a conductor layer. For example, the firstwinding 411 and the bonding material formed from the combined jacketlayers 425 form a first conductor layer. The second winding 413 and thebonding material formed from the combined jacket layers 425 form asecond conductor layer. The bonding material holds the respective wireconductors side-by-side.

FIG. 12B is a side cross-section of a lead body 606, which may includesimilar or identical features as the lead body 206 (FIG. 12A). Forexample, the lead body 606 includes a plurality of wire conductors 680.The lead body 606 is symmetric and includes one or more lumen 602. Alongitudinal axis 690 extends through a geometric center of the lumen602. The lumen 602 is defined by and surrounded by an inner sheath 604.Optionally, an outer surface of the inner sheath 604 may be coated witha layer 620 of an elastomeric polymer, such as a thermoplasticpolyurethane elastomer. A first (or inner) winding 610 and a second (orouter) winding 612 of the wire conductors 680 are wound about the lumen602.

The first and second windings 610, 612 form a multi-layer coil 614 inwhich each of the first and second windings 610, 612 is wound about thelumen 602 and extends at least partially along a length of the lead body606. The first winding 610 includes multiple winding turn segments 627that are wound about the lumen 602 in a first direction (e.g., clockwiseas the wire conductors 680 move toward the distal end of the lead body).The second winding 612 includes multiple winding turn segments 628 thatare wound about the first winding 610 and the lumen 602 in an oppositesecond direction (e.g., counter-clockwise as the wire conductors 680move toward the distal end of the lead body). Each wire conductor 680may be helically wrapped along the lead body 606.

The turn segments 627 of the inner winding 610 are wound about the lumen602 at a designated pitch angle (also referred to as a condensed pitchangle) relative to the longitudinal axis 690. For example, the turnsegments 627 are oriented at an acute pitch angle Θ₁ of between 30 and50° relative to the longitudinal axis 690. The turn segments 628 of thesecond winding 612 are wound about the first winding 610 and the lumen602 at a designated pitch angle relative to the longitudinal axis 690.For example, the turn segments 628 are oriented at an acute pitch angleΘ₂ of between 30 and 50° relative to the longitudinal axis 690. Thefirst and second pitch angles Θ₁ and Θ₂ may be the same (e.g., common)or may be different.

The wire conductors 680 may be similar or identical to the wireconductors 380 (FIG. 12A). The wire conductor 680 is an insulatedconductor having an insulation layer 622 that surrounds a metalconductor 624. Optionally, the wire conductors 680 may be coupled to alead backing 625. The lead backing 625 may comprise a bonding materialand hold the individual wire conductors 680 of a winding in asubstantially fixed position with respect to one another, therebyforming a conductor layer. As shown in FIG. 12B, each of the first andsecond windings 610, 612 is held by a respective lead backing 625 suchthat first and second conductor layers are formed. The lead backing 625may function as an outer sheath in some embodiments. Optionally, anouter sheath (not shown) may surround the second winding 612.

FIG. 13 depicts an image of a distal end of a lead body 430, which maybe similar to the lead body 206 (FIG. 12A) or similar to the lead body606 (FIG. 12B). The lead body 430 includes first and second windings432, 434 of wire conductors 436 that are wrapped about an inner sheath441. At the distal end, the first and second windings 432, 434 may beunwound to form unwound groups 433, 435, respectively. When the wireconductors 436 are joined by a bonding material (e.g., thermoplasticpolyurethane polymer), the unwound groups 433, 435 may be referred to asconductor layers. For example, the unwound group 433 and thecorresponding bonding material may form a first conductor layer. Theunwound group 435 and the corresponding bonding material may form asecond conductor layer.

The unwound groups 433, 435 include segments of the wire conductors 436that project away from the inner sheath 441 in first and seconddirections 442, 444, respectively, such that the lead body 430 has asplayed or butterfly configuration 438. As used herein, a “splayedconfiguration” or “butterfly configuration” includes groups of wireconductors (or conductor layers) that project away from the lumen orinner sheath in different directions. For example, the unwound group 433(or first conductor layer) of the first winding 432 (or first conductorlayer) projects in a first direction 442 along the lead body 430, andthe unwound group 435 of the second winding 434 (or second conductorlayer) projects in a second direction 444 along the lead body 430. Thefirst and second directions 442, 444 may form an acute angle withrespect to a longitudinal axis 446. Values of the acute angles may besimilar to the values of the designated pitch angles. In suchembodiments, the lead body 430 may have only a single inner sheath 441or lumen.

As described above, the individual wire conductors may be held togetherby a bonding material. For example, in FIG. 13, each of the wireconductors 436 of the first and second windings 432, 434 is surroundedby an additional layer of material, such as a jacket layer 425 (FIG.12B). The additional jacket layers may be reflowed to join one another.The combined jacket layers may be referred to as a bonding layer thatcomprises the bonding material of the jacket layers 425. In suchinstances, the unwound groups 433, 435 of the first and second windings432, 434 may form respective conductor layers in which the wireconductors of each winding are held together by the bonding material.

Optionally, the bonding material that holds the wire conductors togethermay exist along each of the first and second windings 432, 434 for adistance. As indicated by the dashed lines, the bonding material may beremoved after this distance to free the wire conductors 436 from thegroups. The bonding material may be removed from the first and secondwindings 432, 434 so that the individual wire conductors 436 may behandled for inserting into the conductor organizers (not shown). Thebonding material may be removed by applying a chemical solvent thatremoves the material of the bonding material. In such embodiments, afirst cross-section of the lead paddle (not shown) that includes thefirst winding 432 prior to the dashed line will have the bondingmaterial. The bonding material may be surrounded by another material,such as the material of the backing layer. But a second cross-section ofthe lead paddle that includes the first winding 432 after the dashedline will essentially not have the bonding material.

For embodiments that include conductor layers, the wire conductors of aconductor layer are separated from one another and inserted through arespective channel. In such embodiments, a cross-section of the leadpaddle may include material other than the bonding material between theindividual wire conductors.

FIG. 14 is an enlarged perspective view of the multi-layered structure340 and the distal end 208 of the lead body 206. At 260 of the method250 (FIG. 4), the distal end 208 of the lead body 206 may be positionedonto the multi-layered structure 340. Prior to positioning, at 260, thedistal end 208 of the lead body 206 or prior to positioning, at 258, theconductor organizers 352A-352D, the wire conductors 380 may be insertedthrough the corresponding channels 354 of the conductors organizers352A-352D. Segments of the wire conductors 380 may be moved (e.g.,pushed or pulled) through the respective side openings 356 or distalopenings 368 (FIG. 9) and positioned adjacent to the respectiveelectrodes 210.

In particular embodiments, the first and second windings 410, 412 of thelead body 206 are arranged in the splayed (or butterfly) configurationin FIG. 14 (and FIG. 15). The lead body 206 may be positioned onto themulti-layered structure 340. The multi-layered structure 340 may have afirst lateral section 390 and a second lateral section 392. As shown,the first and second lateral sections 390, 392 are separated by amidline M_(L) (or midplane M_(P)) of the multi-layered structure 340.Because of the splayed configuration, the wire conductors 380 of thefirst winding 411 are directed toward the first lateral section 390, andthe wire conductors 380 of the second winding 413 are directed towardthe second lateral section 392.

FIG. 15 is an enlarged plan view of the multi-layered structure 340having the wire conductors 380 and the conductor organizers 352A-352Dthereon, and FIG. 16 depicts a wire conductor 380 being mechanically andelectrically coupled to the respective electrode 210. At 262 of themethod 250 (FIG. 4), the wire conductors 380 are electrically coupled tothe respective electrodes 210. The wire conductors 380 extend throughthe conductor passages 328 (FIG. 16) and are positioned onto theelectrode 210. The wire conductors 380 may be welded to the respectiveelectrodes 210. A welding electrode 426 is positioned over the wireconductor 380. A combination of heat and force may displace theinsulation layer 422 (FIG. 12A) and allow the metal conductor 424 (FIG.12A) to be welded to the electrode 210. It is contemplated that othermethods of electrically coupling the wire conductors 380 to theelectrodes 210 may be used.

FIG. 17 depicts a sub-assembly 500 positioned within a mold cavity 502prior to the backing layer 218 (FIG. 2) being added. The method 250(FIG. 4) also includes inserting an elongated mandrel 504, at 264,through the lumen 402 of the lead body 206. In the illustratedembodiment, the mandrel 504 extends entirely through the cavity 502. Thesub-assembly 500 includes the multi-layer structure 340, the conductororganizers (referenced generally as 352), the wire conductors 380electrically coupled to the electrodes 210, the distal end 208 of thelead body 206, and the mandrel 504. The method 250 (FIG. 4) alsoincludes positioning, at 266, the sub-assembly 500 within the cavity 502and molding, at 268, the backing layer 218 to the multi-layeredstructure 340. The backing layer 218 may comprise, for example, a highconsistency rubber (HCR) silicone, also known as gum stock silicone.After removing the lead paddle 200 from the cavity 502, the contact side202 (FIG. 2), among other things, may be cleaned, at 270.

FIG. 18 is an end view of the lead paddle 200, and FIG. 19 illustrates across-section of the lead paddle 200 taken along lines 19-19 in FIG. 3.As shown, the lead paddle 200 has a thickness T that is determined bythe flexible layer 216 and the backing layer 218. Optionally, an opening506 left by the mandrel 504 (FIG. 17) may be filled. As shown, thebacking layer 218 is shaped to define the raised portions 232 and therecessed portions 234 along the back side 204. The raised portions 232are separated by the recessed portions 234, and the recessed portions234 are separated by the raised portions 232. In the illustratedembodiment, the raised portions 232 are elongated ridges that extendparallel to one another. The recessed portions 234 are elongated groovesor open-sided channels that extend parallel to one another.

Also shown in FIG. 18, the lead paddle 200 may be divided into a firstlateral section 590 and second lateral section 592. As shown, the firstand second lateral sections 590, 592 of the lead paddle 200 areseparated by the midline M_(L) (or the midplane M_(P)).

As shown in FIG. 19, in some embodiments, at least some of the recessedportions 234 of the backing layer 218 and at least some of the recessedregions 224 of the flexible layer 216 align with one another at thinsections 294 of the lead paddle 200. At least some of the raisedportions 232 of the backing layer 218 and at least some of the raisedregions 222 of the flexible layer 216 align with one another at thicksections 296 of the lead paddle 200. The aligned recessed portions 234and recessed regions 224 may enable flexing by the lead paddle 200. Thelead paddle 200 may more readily flex about the thin sections 294 thanthe thick sections 296. In some embodiments, the raised portions 232 mayengage scar tissue within the epidural space that reduces the likelihoodof migration.

By way of example, a spacing 295 between adjacent electrodes 210 may be0.039 inches (or 0.9906 mm). A width D₂ of the between recessed region224 may be 0.030 inches (0.762 mm). However, it should be understoodthat alternative embodiments may have other pitches or widths. In someembodiments, the spacing 295 exists between adjacent columns 360 suchthat the columns 360 are separated by the spacing 295. This spacing 295is similar to the spacing 492 (FIG. 11). The spacing 295 is a region ofthe paddle body 212 (FIG. 2) that exists between the electrodes 210(FIG. 2). The spacing 295 may include portions of the paddle body 212and is not required to be empty space, although it may include emptyspace.

FIG. 20 is a cross-section of the lead paddle 200 that includes one ofthe conductor organizers 352 and a plurality of the wire conductors 380received within respective channels 354. In the illustrated embodiment,the channels 354 of the conductor organizer 352 extend along andparallel to the second side surface 304 of the inner frame 220. Thechannels 354 of the conductor organizer 352 may extend along the spacing295 between the columns 360 of the electrodes 210. One of the wireconductors 380 extends through a side opening 356 of the conductororganizer 352 and into a conductor passage 328 of the lead paddle 200.The wire conductor 380 is terminated to an electrode 210. As shown, aframe window 306 of the inner frame 220 and a layer window 326 of theflexible layer 216 are aligned to form the conductor passage 328. Afterthe backing layer 218 is applied to the multi-layered structure 340, thematerial of the backing layer 218 may be disposed within the conductorpassage 328. At least a portion of the channels 354 may be filled withthe material of the backing layer 218.

The recessed portion 234 of the backing layer 218 where the conductororganizer 352 is disposed has a layer thickness 520. The conductororganizer 352 has an organizer height 522, and the wire conductor 380has a diameter 524. The layer thickness 520 may be configured toaccommodate the organizer height 522. For example, the layer thickness520 may be at least 10% greater than the organizer height 522 or, moreparticularly, at least 20% greater than the organizer height 522. Insome embodiments, the layer thickness 520 is at least 0.051 mm (0.002in) greater than the organizer height 522.

The layer thickness 520 of the recessed portion 234 may be, for example,at most 0.508 mm (0.020 in). In certain embodiments, the layer thickness520 at the recessed portion 234 may be, for example, at most 0.381 mm(0.015 in) or, more particularly, at most 0.305 mm (0.012 in) or, moreparticularly, at most 0.254 mm (0.010 in). The organizer height 522 ofthe conductor organizer 352 prior to deformation may be, for example, atmost 0.381 mm (0.015 in). In certain embodiments, the organizer height522 prior to deformation may be, for example, at most 0.305 mm (0.012in) or, more particularly, at most 0.229 mm (0.009 in) or, even moreparticularly, at most 0.203 mm (0.008 in). The diameter 524 of the wireconductor 380 may be, for example, at most 0.125 mm (0.050 in). Moreparticularly, the diameter 524 of the wire conductor 380 may be, forexample, at most 0.090 mm (0.035 in).

It should be understood that the above upper limits and relationshipsare provided as examples that may be used with some embodiments.Embodiments may have upper limits or relationships defined by valuesthat are greater than or less than the values provided above.

In FIG. 20, the conductor organizer 352 is shown in an uncompressed ornon-deformed condition. In some embodiments, the conductor organizer 352may be compressed and deformed (e.g., crushed) during manufacture suchthat the size of the channel 354 is reduced. Specifically, the organizerheight 522 may be reduced and the channel 354 may be collapsed aroundthe wire conductor 380. In some embodiments, the material of the backinglayer 218 may flow into the channel 354 during the molding, at 268, andsolidify therein. Air pockets may or may not exist within the channels354 after molding at 268.

Optionally, embodiments set forth herein have wire conductors that arepositioned within the lead paddle (or the paddle body) to reducestresses experienced by the wire conductors when the lead paddle isflexed. The wire conductors may be positioned along or near a neutralplane. A neutral plane is a conceptual plane that is used in engineeringdesign. When a structure is flexed or bent in a direction that istransverse to the neutral plane, the neutral plane separates one regionthat is in compression and one region that is in tension.

As describe above, embodiments may be configured to reduce thelikelihood that the wire conductors will break and/or separate from theelectrodes. As such, the wire conductors may be positioned within theNLFE for at least a portion of the length of the lead paddle. When thelead paddle is flexed or bent, the NLFE may experience a compressionstress on one side of the neutral plane that is less than thecompression stress experienced outside the NLFE. On the other side ofthe neutral plane, the NLFE may experience a tensile stress that is lessthan the tensile stress experienced outside the NLFE. Lead paddles maybe configured to control the amount of stress (whether tensile orcompression) and thereby reduce the likelihood that the connections tothe electrodes will fail.

As shown in FIG. 20, a portion of the NLFE is represented by a box 530.Because the lead paddle 200 or the paddle body 212 can have a complexthree-dimensional shape (as partially shown in FIG. 20), the NLFE 530 isnot necessarily a planar structure having two parallel sides and auniform thickness. The NLFE 530 includes a neutral plane NP of thepaddle body 212 or the lead paddle 200. The neutral plane NP extendssubstantially parallel to the XY plane.

The wire conductors 380 may be positioned within the lead paddle 200 tomodulate the stresses experienced by the wire conductors 380 due toflexing. For example, when the lead paddle 200 is flexed transverse tothe Y axis (or transverse to the longitudinal axis 290 (FIG. 3)) suchthat a distal section is bent downward relative to the XY plane, theportion of the lead paddle 200 that is below the neutral plane NP nearthe bend is compressed. The portion of the lead paddle 200 that is abovethe neutral plane NP near the bend is stretched. The NLFE 530experiences a compression stress that is less than the compressionstress experienced by the lead paddle 200 outside of the NLFE 530. TheNLFE 530 experiences a tensile stress that is less than the tensilestress experienced by the lead paddle 200 outside of the NLFE 530. Thestresses within the NLFE 530 may be controlled to reduce the likelihoodthat the electrical connections to the electrodes will be broken.

Conversely, when the lead paddle 200 is flexed transverse to the Y axis(or transverse to the longitudinal axis 290 (FIG. 3)) such that a distalsection is bent upward relative to the XY plane, the portion of the leadpaddle 200 that is below the neutral plane NP near the bend isstretched. The portion of the lead paddle 200 that is above the neutralplane NP near the bend is compressed. The NLFE 530 experiences acompression stress that is less than the compression stress experiencedby the lead paddle 200 outside of the NLFE 530. The NLFE 530 experiencesa tensile stress that is less than the tensile stress experienced by thelead paddle 200 outside of the NLFE 530. Again, the stresses within theNLFE 530 may be controlled to reduce the likelihood that the electricalconnections to the electrodes will be broken.

In some embodiments, the inner frame 220 at least partially determines alocation of the NLFE 530. More specifically, properties of the innerframe 200, when secured to the backing layer 218, may determine alocation of the NLFE 530 within the lead paddle 200. In such instances,a wire conductor may be within the NLFE when a center of the wireconductor is within a designated distance from the inner frame. Forexample, the wire conductor 380 is within the NLFE 530 when a center 538of the wire conductor 380 is separated from the second side surface 304of the inner frame 220 by a distance 540 that is at most two-and-a-halftimes (2.5×) the diameter 524 of the wire conductor 380. In particularembodiments, the wire conductor 380 is within the NLFE 530 when a center538 of the wire conductor 380 is separated from the second side surface304 of the inner frame 220 by a distance 540 that is at most two times(2×) the diameter 524 of the wire conductor 380. In more particularembodiments, the wire conductor 380 is within the NLFE 530 when thedistance 540 is at most one-and-a-half times (1.5×) the diameter 524 ofthe wire conductor 380.

The minimum thickness 542 is the shortest distance between the contactside 202 and the back side 204. Optionally, the NLFE 530 is locatedwithin a middle one-half of a minimum thickness 542 of the thin section294. More specifically, at least one quarter of the thickness of thethin section 294 may be above the NLFE 530 and at least one quarter ofthe thickness may be below the NLFE 530. In more particular embodiments,the NLFE 530 is located within a middle one-third of a minimum thickness542 of the thin section 294. More specifically, at least one third ofthe thickness of the thin section 294 may be above the NLFE 530 and atleast one third of the thickness may be below the NLFE 530.

Optionally, the NLFE 530 may have a thickness 536 that is at most fivetimes (5×) a diameter of the wire conductor. In particular embodiments,the NLFE 530 may have a thickness 536 that is at most three times (3×) adiameter of the wire conductor or, more particularly, a thickness 536that is at most two times (2×) a diameter of the wire conductor.

In some embodiments, at least one or more sections of the inner frame220 (or the entire inner frame 220) may be positioned within or adjacentto the NLFE 530. For example, the second side surface 304 of the innerframe 220 may include neutral force lanes 532 that are disposed withinor adjacent to the NLFE 530. For embodiments that include the thinsections 294, the neutral force lanes 532 may extend along and throughthe thin sections 294 of the lead paddle 200. In FIG. 20, the neutralforce lane 532 extends between columns 360 of the electrodes 210. Thesecond side surface 304 of the inner frame 220 may also include awire-void area 534. In FIG. 20, the wire-void area 534 of the innerframe 220 aligns with the non-contact faces 345 of the electrodes 210 ofa single column 360.

In the illustrated embodiment, the neutral force lanes 532 are linearand extend between the columns 360. In other embodiments, the neutralforce lanes 532 may curve and/or cross over a column without crossingover the wire-void areas 534.

In particular embodiments, the conductor organizers 352 route the wireconductors 380 along the neutral force lanes 532 so that stressesexperienced by the wire conductors 380 are not excessive. Alternativelyor in addition to the above, the conductor organizers 352 may preventthe wire conductors 380 from crossing over one another and crossing overthe wire-void areas 534 (or over the projections 344, 346 (FIG. 8A)). Assuch, the likelihood of the wire conductors breaking or otherwisecausing the electrodes to fail may be reduced.

A wire conductor is not required to extend along the NLFE for the entirelength of the lead paddle. In some embodiments, a wire conductor mayreside within the NLFE if a center of the wire conductor is separatedfrom the second side surface of the inner frame by at most apredetermined distance (e.g., at most 2.5× or 2× of the diameter) for atleast half of the length of the lead paddle. In some embodiments, a wireconductor may reside within the NLFE if a center of the wire conductoris separated from the second side surface of the inner frame by at mosta predetermined distance (e.g., at most 2.5× or 2× of the diameter) forat least the last half of the length of the lead paddle. In other words,the half of the lead paddle that includes a distal end of the leadpaddle. In particular embodiments, a wire conductor may reside withinthe NLFE if a center of the wire conductor is separated from the secondside surface of the inner frame by at most a predetermined distance(e.g., at most 2.5× or 2× of the diameter) for at least three quartersof the length of the lead paddle including the distal end of the leadpaddle.

In some embodiments, the lead paddles set forth herein may bemanufactured without conductor organizers. In such embodiments, the wireconductors may be positioned, as described herein, such that the wireconductors extend longitudinally between columns of the electrodesand/or the wire conductors do not cross over one another and/or the wireconductors do not cross over the electrodes (e.g., projections of theelectrodes). For example, the wire conductors may be clamped at one orboth ends of the paddle body as the backing layer is molding.

It may be noted that the various embodiments may be implemented inhardware, software or a combination thereof. The various embodimentsand/or components, for example, the modules, or components andcontrollers therein, also may be implemented as part of one or morecomputers or processors. The computer or processor may include acomputing device, an input device, a display unit and an interface, forexample, for accessing the Internet. The computer or processor mayinclude a microprocessor. The microprocessor may be connected to acommunication bus. The computer or processor may also include a memory.The memory may include Random Access Memory (RAM) and Read Only Memory(ROM). The computer or processor further may include a storage device,which may be a hard disk drive or a removable storage drive such as asolid-state drive, optical disk drive, and the like. The storage devicemay also be other similar means for loading computer programs or otherinstructions into the computer or processor.

As used herein, the term “computer,” “subsystem,” “controller circuit,”“circuit,” or “module” may include any processor-based ormicroprocessor-based system including systems using microcontrollers,reduced instruction set computers (RISC), ASICs, logic circuits, and anyother circuit or processor capable of executing the functions describedherein. The above examples are exemplary only, and are thus not intendedto limit in any way the definition and/or meaning of the term“controller circuit”.

The computer, subsystem, controller circuit, circuit execute a set ofinstructions that are stored in one or more storage elements, in orderto process input data. The storage elements may also store data or otherinformation as desired or needed. The storage element may be in the formof an information source or a physical memory element within aprocessing machine.

The set of instructions may include various commands that instruct thecomputer, subsystem, controller circuit, and/or circuit to performspecific operations such as the methods and processes of the variousembodiments. The set of instructions may be in the form of a softwareprogram. The software may be in various forms such as system software orapplication software and which may be embodied as a tangible andnon-transitory computer readable medium. Further, the software may be inthe form of a collection of separate programs or modules, a programmodule within a larger program or a portion of a program module. Thesoftware also may include modular programming in the form ofobject-oriented programming. The processing of input data by theprocessing machine may be in response to operator commands, or inresponse to results of previous processing, or in response to a requestmade by another processing machine.

As used herein, the terms “software” and “firmware” are interchangeable,and include any computer program stored in memory for execution by acomputer, including RAM memory, ROM memory, EPROM memory, EEPROM memory,and non-volatile RAM (NVRAM) memory. The above memory types areexemplary only, and are thus not limiting as to the types of memoryusable for storage of a computer program.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from its scope. While the dimensions, types ofmaterials and coatings described herein are intended to define theparameters of the invention, they are by no means limiting and areexemplary embodiments. Many other embodiments will be apparent to thoseof skill in the art upon reviewing the above description. The scope ofthe invention should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Moreover, in the following claims, theterms “first,” “second,” and “third,” etc. are used merely as labels,and are not intended to impose numerical requirements on their objects.Further, the limitations of the following claims are not written inmeans—plus-function format and are not intended to be interpreted basedon 35 U.S.C. § 112(f), unless and until such claim limitations expresslyuse the phrase “means for” followed by a statement of function void offurther structure.

What is claimed is:
 1. An implantable stimulation lead for stimulationof neural tissue of a patient, comprising: an elongated lead body havingdistal and proximal ends and wire conductors extending therebetween; anda paddle structure adapted to be implanted adjacent to neural tissue forelectrical stimulation, the paddle structure comprising a flexiblepolymer body, electrodes arranged in a multi-dimensional pattern andpositioned along a contact side of the flexible polymer body, and aplurality of sets of microtubes with each microtube having an innerlumen; wherein (1) the electrodes are electrically coupled to the wireconductors of the lead body through wires positioned within the innerlumens of the plurality of sets of microtubes, (2) each set ofmicrotubes are positioned to extend along the paddle structure, and (3)the polymer body of the paddle structure flexes transversely about itslongitudinal axis and the plurality of sets of microtubes are arrangedgenerally parallel to the longitudinal axis.
 2. The stimulation lead ofclaim 1 wherein distal ends of the conductor wires of the lead body areplaced within the inner lumens of the plurality of sets of microtubesand are directly electrically connected to the electrodes.
 3. Thestimulation lead of claim 1 wherein the electrodes are connected to thewire conductors of the lead body through one or more intermediateconductor elements.
 4. The stimulation lead of claim 1, wherein each setof the plurality of sets of microtubes comprise multiple microtubes thatare connected to one another in a side-by-side configuration.
 5. Thestimulation lead of claim 1, wherein the paddle structure comprises aninner frame having opposite first and second side surfaces and a polymerlayer secured to the first side surface of the inner frame, the polymerlayer defining a portion of the contact side of the lead paddle, theinner frame being more rigid than the polymer layer, and the pluralityof sets of microtubes extend along the second side surface of the innerframe.
 6. The stimulation lead of claim 1, wherein the electrodes arearranged in columns that extend longitudinally along the lead paddle andeach set of the plurality of sets of microtubes extend longitudinallybetween adjacent columns of electrodes.
 7. The stimulation lead of claim6, wherein the columns include first and second columns that areadjacent to one another with a respective set of microtubes extendinglongitudinally between the first and second columns, wherein at leastone of the wires within the inner lumen of one microtube of therespective set is connected to one of the electrodes of the first columnand at least one of the wires within the inner lumen of one microtube ofthe respective set is connected to one of the electrodes of the secondcolumn.
 8. The stimulation lead of claim 1, wherein the openings of themicrotubes are positioned adjacent to the respective electrodes, theopenings include at least one side opening and at least one distalopening, the distal opening is at an end of at least one set ofmicrotubes, and the side opening is spaced apart from the at least onedistal opening.
 9. The stimulation lead of claim 1, wherein the sets ofmicrotubes are arranged so that wires within the microtubes do not crossover each other on the paddle structure.
 10. The stimulation lead ofclaim 1, wherein (1) the paddle structure comprises an inner frameenclosed within the flexible polymer body, (2) the inner frame comprisesa plurality of grooves extending longitudinally along the frame, and (3)each set of the plurality of sets of microtubes is located below arespective groove of the inner frame to define a fold line about whichthe paddle structure flexes transversely relative to the longitudinalaxis of the paddle structure.
 11. A method of fabricating an implantablestimulation lead for provision of electrical stimulation to tissue of apatient, the method comprising: providing a paddle structure adapted tobe implanted adjacent neural tissue for electrical stimulation, thepaddle structure comprising a flexible polymer body; providingelectrodes arranged in a multi-dimensional pattern and positioned alonga contact side of the flexible polymer body; providing a plurality ofsets of microtubes with each microtube having an inner lumen on theflexible polymer body; routing a wire through each respective microtubeof the plurality of sets of microtubes; and electrically coupling thewires within plurality of sets of microtubes to respective electrodespositioned along a contact side of the flexible polymer body, whereinthe polymer body of the paddle structure flexes transversely about itslongitudinal axis and the plurality of sets of microtubes are arrangedgenerally parallel to the longitudinal axis.
 12. The method of claim 11wherein the routing a wire through each respective microtube comprisesinserting a respective conductor wire from a lead body through the innerlumen of each respective microtube.
 13. The method of claim 11 furthercomprising: forming a respective opening for each microtube of theplurality of sets of microtubes; removing a portion of the wire from theinner lumen of each microtube; and electrically connecting the removedportion of the wire from each microtube to an electrode.
 14. The methodof claim 13 wherein the electrically connecting the removed portion ofthe wire comprises welding the removed portion of the wire to anelectrode.
 15. The method of claim 11 wherein the paddle structurecomprises an inner frame having opposite first and second side surfaces,the electrodes are provided on the first side of the inner frame, andthe plurality of sets of microtubes extend along the second side surfaceof the inner frame.
 16. The method of claim 11 wherein the routing aconductor through each respective microtube comprises: applying achemical solvent to release segments of conductor wires bonded to thefirst and second backing layers.
 18. The method of claim 11 wherein thepaddle structure comprises an inner frame having opposite first andsecond side surfaces, the electrodes are provided on the first sidesurface of the inner frame, and the plurality of sets of microtubes areprovided to extend along the second side surface of the inner frame. 19.The method of claim 1, wherein each set of the plurality of sets ofmicrotubes comprise multiple microtubes that are connected to oneanother in a side-by-side configuration.
 20. The method of claim 11,wherein (1) the paddle structure comprises an inner frame, (2) the innerframe comprises a plurality of grooves extending longitudinally alongthe frame, (3) each set of the plurality of sets of microtubes islocated below a respective groove of the inner frame to define a foldline where the paddle structure flexes transversely relative to thelongitudinal axis of the paddle structure.